Deciding To Tune Buffers - Dell S6100 Configuration Manual

similar to the following displays: % Info: For the global pre-defined buffer profile to take effect, please
save the config and reload the system.
Dell Networking OS Behavior: After you configure buffer-profile global 1Q, the message displays during every bootup. Only one reboot is
required for the configuration to take effect; afterward you may ignore this bootup message.
Dell Networking OS Behavior: If you configure 1Q, save the running-config to the startup-config, and then delete the startup-config and
reload the chassis. The only way to return to the default buffer profile is to remove the 1Q profile configured and then reload the chassis.
If you have already applied a custom buffer profile on an interface, the buffer-profile global command fails and a message similar
to the following displays: % Error: User-defined buffer profile already applied. Failed to apply global
pre-defined buffer profile. Please remove all user-defined buffer profiles.
Similarly, when you configure buffer-profile global, you cannot not apply a buffer profile on any single interface. A message similar
to the following displays: % Error: Global pre-defined buffer profile already applied. Failed to apply
user-defined buffer profile on interface Te 1/1. Please remove global pre-defined buffer
profile.
To apply a predefined buffer profile, use the following command.
• Apply one of the pre-defined buffer profiles for all port pipes in the system.

Deciding to Tune Buffers

Dell Networking recommends exercising caution when configuring any non-default buffer settings, as tuning can significantly affect system
performance. The default values work for most cases.
As a guideline, consider tuning buffers if traffic is bursty (and coming from several interfaces). In this case:
• Reduce the dedicated buffer on all queues/interfaces.
• Increase the dynamic buffer on all interfaces.
• Increase the cell pointers on a queue that you are expecting will receive the largest number of packets.
To define, change, and apply buffers, use the following commands.
• Define a buffer profile for the FP queues.
CONFIGURATION mode
buffer-profile fp fsqueue
• Define a buffer profile for the CSF queues.
CONFIGURATION mode
buffer-profile csf csqueue
• Change the dedicated buffers on a physical 1G interface.
BUFFER PROFILE mode
buffer dedicated
• Change the maximum number of dynamic buffers an interface can request.
BUFFER PROFILE mode
buffer dynamic
• Change the number of packet-pointers per queue.
BUFFER PROFILE mode
Debugging and Diagnostics 977